Fluid pressure operated torque wrench



M y 1953 F. R. RAY 2,836,090

FLUID PRESSURE OPERATED TORQUE WRENCH Filed Feb. 21, 1957 2 Sheets-Sheet1 8 FLU/D PBESSURE SOURCE INVENTOR.

FEA/VK e. 24v, 7

A TTOQ/VEYS.

May 27, 1958 F. R. RAY

FLUID PRESSURE OPERATED TORQUE WRENCH 2 Sheets-Sheet 2 Filed Feb. 21,1957 INVENTOR. tea/vie 2. 94v,

United States atent FLUID PRESSURE OPERATED TORQUE WRENCH Frank R. Ray,Ashland, Greg.

Application February 21, 1957, Serial No, 641,687

3 Claims. (Cl. 81-54) This invention relates to an improved fluidpressure operated torque wrench for use in limited and confined spaces.

The primary object of the invention is to provide a more practical andefl-lcient wrench of this kind which is more easily inanipulable andoperated, and which is simpler in construction, being composed of asmall number of simple and easily assembled and disassembled parts.

Another object or" the invention is to provide a fluid pressure operatedwrench of the character indicated above which can be made inwell-finished, rugged, and serviceable forms at relatively low cost, iseasily used and maintained, and is highly acceptable for the purposeintended.

These together with other objects and advantages which will becomeapparent reside in the details of construction and operation as morefully hereinafter described and claimed, reference being had to theaccompanying drawings forming a part thereof, wherein like numeralsrefer to like parts throughout the several views, and in which:

Figure 1 is a schematic perspective view of a fluid pressure operatedtorque wrench of the invention including means for operating the same;

Figure 2 is a forward end elevational view of the torque wrench ofFigure 1;

Figure 3 is a longitudinal sectional view taken substantially on line 33of Figure 2;

Figure 4 is a vertical transverse sectional view taken substantially online 44 of Figure 1; and

Figure 5 is a vertical transverse sectional view taken substantially online 55 of Figure 1.

Referring to the drawings in detail, the illustrated fluid pressureoperated torque wrench, indicated generally at 10, includes a torquewrench 12 to which is connected a hose 14 leading from a fluid pressuretorque indicating gauge 16, which in turn is connected to a fluidpressure source, indicated generally at 18.

The torque wrench 12 comprises an elongated cylinder 29 having a bore 22closed at the rear end by a threaded cap 26 having a threaded centralopening 24 therein. Threaded in the opening 24 is a nipple 28 to whichis connected a flexible hose 14. Working in the cylinder bore 22 is apiston 30 which has thereon a plurality of sealing rings 32. The piston30 is fixed on the rear end of an elongated rack bar 36 which has alongone side thereof longitudinally spaced rack teeth 38. As seen in Figures1 and 3, the forward end of the cylinder is reduced, as indicated at 40,and has a reduced bore portion 46 which conforms to and slidably andnonrotatably supports the rack bar 26.

The reduced forward end portion 40 of the cylinders by studs 48, and thecover plate 50 and the bottom wall 52 of the housing 42 have thereinaligned axial bores 54 and 56, respectively. The aligned bores 54 and 56have journaled therein stub shafts 57 and 58, respectively, on oppositesides of a pinion gear 60, whose teeth 62 are meshed with the rack teeth38 of the rack bar 36. The stub shafts 57 and 58 terminate in polygonalbosses 64 and 66, respectively, rectangular as shown in Figure 1, forexample. The bosses have in their sides spring-urged ball detents 68 forholding on the bosses 64 and 66, desired wrench sockets (not shown).

The fluid pressure source 18, which can be of any suitable motoroperated or manually operated form, as shown as including a cylinder 70having pivoted thereon a manual lever 72 connected to a piston 74 andoperable for supplying fluid pressure through the gauge 16, and the hose14 to the wrench cylinder 20. The scale of the gauge 16 is graduated toindicate foot-pounds of torque applied to the wrench 12. The cylinder 70of the fluid pressure source 18 incorporates therein manual pressurerelief valve means 76 for relieving the pressure in the wrench cylinder20, after a bolt, nut, or the like has been tightened by the wrench at apredetermined torque, to enable manual retraction of the rack bar 36, toset it for another tightening operation, either by pushing the rack bar36 into the cylinder 20, or by rotating the pinion gear by applicationof a tool to one of the bosses 64 and 66.

In order to obtain reverse rotation or loosening of a nut or bolt, thepertinent wrench socket (now shown) is removed from one of the bosses 64and 66 and applied to the other boss, and the socket then applied to thenut or bolt concerned.

Fixed on and extending laterally from the rear end portion of thecylinder 2%,- at the same side and in the same plane as the housing 42,is a lug 76 having therein a transverse bore 78, see Figures 3 and 5, inwhich is slidably engaged a removable rod 80 having in a side thereof atopposite ends thereof spring-urged ball detents 82 which retain the rod80 in the bore 78. When pressed inwardly, the detents permit removal ofthe rod 80 from the lug 76. The rod 86) is provided for engagement witha portion of such as an engine block, to prevent vagrant rotation of thewrench while a rotatable fastening element is being tightened orloosened.

In operation, with the rack 36 in the position of Figure 3, and the rod80 bearing against a piece of machinery in which a nut or bolt is to betightened down, a wrench socket is placed on the boss 64, Figure 2, andslipped over the nut or bolt to be tightened, whereupon the lever 72 ispressed downwardly toward the cylinder 76, resulting in the actuation ofthe piston 74 to force fluid through the hose 14 into the cylinder 20and move 20 includes a laterally extending substantially semi- 1 therack 36 and pinion gear 60 to tighten down the nut or bolt. After thisis done, the valve means 76 is opened, the wrench socket is then removedfrom the tightened nut or bolt and the boss 64. The rack is thenmanually pushed back into the cylinder 26 and is then ready for anothertightening operation. The amount of pounds pressure employed fortightening down the bolt or nut is read upon the gauge 16.

To loosen a tightened down nut or bolt the operating procedure above setforth is the same, except that the wrench socket is placed upon the boss66 and slipped over the tightened nut or bolt.

The foregoing is considered as illustrative of the principles of theinvention. Since numerous modifications and changes will readily occurto those skilled in the art, it is not intended or desired to limit theinvention to the exact construction and operation shown and described,and accordingly all suitable modifications and equivalents may beresorted to, as fall within the scope tio i mean pr cluding rotation ofsaid rack bar rela iv o i reduced yl nder P Q A and the cylin r, a bonins xed on said one si e of said re uced cylinder porti n an inroi c inglaterally herefromsaid housing having a bot om. wall and an open sidefacingsaid bott m wall, a coverplate s cured to said one si said c ver pa e and aid ottomw'wall having aligned axial bOres,ya pinion gear insaid housing between said bottom wall and said cover plate llayingrstub'shafts on opposite sides thereof journaled in related ones of said axialbores, said pinion ear having tee h meshed with said ra k t p yg nalwrench socket receiving bosses on said stub shafts, and means f radmitting and releasing fluid pressure to the cylinder between thepiston and the rear end of the yli der.

I 2; In a fluid pressure operated wrench, yanxelongated cylinder havinga forward end and a rear end and an axial bore, closure .means'closingthe rear end of the cylinder bore, a reduced portion on the forward endof the cylinder having therein a reduced bore portion aligned with andopening into the cylinder bore, a piston Working in the cylinder borehaving thereon a forwardly extending rack bar smaller in diameter thanthe piston and sliding in said reduced bore portion, said rack barhaving therealong rack teeth facing one side of said reducedcylinderportion, means precluding rotation of said rack bar relative tosaid reduced'cylinder portion and the cylinder, a hous- 3. In a fluidpressure operated wrench, an elongated cylinder having a forward end anda rear end and an axial bore, closure means closing the rear end of thecylinder bore, a reduced portion on the forward end of the cylinderhaving therein a reduced bore portion aligned with and opening into thecylinder bore, a piston working in the cylinder borehaving thereon aforwardly extending rack bar smaller in diameter than the piston andsliding in said reduced bore portion,-said rack oar having erealong rackteeth facing one side of said reduced cylinder portion, means precludingrotation of said rack bar relative to said reduced cylinder portionandthe cylinder, a housing fixed on said one sidelof said reducedcylinder portion and projecting laterally therefrom, said housing havinga bottom wall and an open side'facing said bottom wall, a cover platesecured to' said one side, said cover plate and said bottom wall havingaligned axial bores,

a pinion gear in *said housing between said bottom wall and said coverplate having stub shafts on opposite sides thereof journaled in relatedones of said axial bores, said,

pinion gear having teeth meshed with said rack teeth,

polygonal Wrench socket receiving bosses on said stub shafts, and means'for admitting and releasing fluid pressure to the cylinder between thepiston and the rear end ing fixed on said one side of said reducedcylinder porsaid cover plate having stub shafts on opposite sidesthereof journaled in related ones of said axial bores, said pinion gearhaving teethmeshed with said rack teeth, polygonal wrench socketreceiving bosses on said stub shafts, and

of the cylinder, and arm means'o'n and extending iaterally fromsaidcylinder for engagement with a portion of a workpiece on which thewrench is used, for preventing vagrant rotation "of the wrench relativeto the workpiece during operation of the wrench. s r

7 References Cited in the file of this patent UNITED STATES PATENTS 1 i1,808,959 Lane et "al. June 9, 1931 2,398,392 Page -n. Apr. 16, 1,9462,560,716 Bortle et -al. July 17, 195] 2,594,964 Meyers Apr. 29, 1952'2,760,393 Stough Aug. 28, 1956 2,786,379 Blackinton Mar. 26, 1957FOREIGN PATENTS 7 897,420

' France May 22, 1944

